I have tried to export the latest setting of the SEO plugin and I got the below error I have replaced the site name with example. FYI
Warning: chdir() [function.chdir]: No such file or directory (errno 2) in /home/username/example.com/wp-content/plugins/wordpress-seo/inc/wpseo-non-ajax-functions.php on line 90
I tried this on another install of WordPress on a different on Linux server and got the same error.
Warning: chdir() [function.chdir]: No such file or directory (errno 2) in /home/username/public_html/wp-content/plugins/wordpress-seo/inc/wpseo-non-ajax-functions.php on line 90
But I was able to do an export in previous versions of your plugin.